1. Technical Field
This disclosure relates generally to noise attenuation for an aircraft propulsion system.
2. Background Information
A propulsion system for an aircraft produces varying amounts of audible noise during operation. One or more acoustic panels may be configured with the propulsion system to attenuate and reduce this noise. As a general rule with known technology, relatively thin acoustic panels are utilized to attenuate noise with relatively short wavelengths and high frequencies, whereas relatively thick acoustic panels are utilized to attenuate noise with relatively long wavelengths. However, as noise wavelengths lengthen as a byproduct of new engine designs while space allocation for sound attenuation structures decreases, traditional acoustic panel configurations may not fulfill all their requirements. There is a need in the art for an improved sound attenuation structure for an aircraft propulsion system that attenuates longer wavelength, low frequency noise without being excessively thick.